


it's a damned fine game (and we can play all night)

by AngelicSentinel



Category: Magic Kaito, 名探偵コナン | Detective Conan | Case Closed
Genre: Alpha/Beta/Omega Dynamics, Come Marking, Comeplay, Excessive Come, Knotting, Lactation Kink, M/M, Male Lactation, Mating Bites, Mating Cycles/In Heat, Mpreg, Omega Verse, Plot What Plot/Porn Without Plot, Possessive Behavior, Scent Kink, Scent Marking, Scenting, Shower Sex
Language: English
Status: In-Progress
Published: 2018-05-24
Updated: 2018-12-19
Packaged: 2019-05-13 04:57:24
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 12,539
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14742401
Author URL: https://archiveofourown.org/users/AngelicSentinel/pseuds/AngelicSentinel
Summary: That smell from earlier. It's him. He smells like expensive cologne and the spice of sex, and it covers his own like a caress, faint but unmistakably alpha.





	1. let loose lips kiss you clean

**Author's Note:**

> [Request Fic.](https://archiveofourown.org/works/14207484/comments/163505835) a/b/o is a place I'd never thought I'd go, but it was incredibly fun to write. 
> 
> omega!Kaito, alpha!Shinichi, but when I write kaishin, they're always vers, including this fic.
> 
> Some possessive behavior, but I don't think it's bad enough to tag for. Warning just in case. 
> 
> Oh, and they're technically intersexed. So no usual a/b/o cloaca. Alpha & beta males can't conceive, omega men can. Alpha females can but struggle with fertility, beta & omega women can.
> 
> Only omegas go into heat. Rut is just the term for territorial and scent displays. Betas can conceive all year, omegas only can during estrus.
> 
> Musk is the term for scent produced by glands near the genitals and inner thighs.

His heat hits him like a freight train in the middle of a heist.

It's not supposed to happen for another couple of months.

His body disagrees.

It's all Kaito can do to make it out of the exhibition room of the hotel and crawl into an unused conference room, unhooking his cape and sealing the room as much as the cloth will allow by stuffing the cloth at the gap under the door. It won't stop his scent from escaping, but it will cause it to be fainter, and that may be the difference between escape and capture.

That done, he listens to the bug he planted as he leans back against the wall, sweating profusely. “He's escaping from the roof! Get after him!” Nakamori bellows, and Kaito lets himself relax, but only just. The diversion worked.

He wipes the synthetic scent gel he uses for KID and covers it with a different one, a random male, placing it directly over his scent glands below his jaw. On his cheeks, wrists, palms, temple, small of his back. It will cover the scent emanating from them entirely. For a time. At least until his heat smell soaks through.

Kaito thinks of the faint spice, the tantalizing whisper he'd caught as he'd snagged the ruby necklace with the glittering diamonds surrounding it, and his stomach twists, a trill of trembling energy racing through him, leaving him harder than he was when he first caught it.

The next item on his list is sending a mail to Jii to let him know what's going on. His heat lasts several days, and he can’t spend it all in this conference room, as appealing as that idea sounds. Someone will definitely find him. The door opens outward too, so no barricading it.

Kaito loosens his tie, spreading his legs to try to ease the discomfort between them. The temptation to palm himself through his trousers is almost too much, and it’s highly counterproductive, given he's trying to get rid of his scent, not strengthen it, so he pulls out a deck of cards, occupying his hands with basic one-handed cuts, interspersing it with more involved card flourishes: Sybil with its face up flips, Charlier, Scissor, a Tornado spin into the Pandora sequence. He's too practiced for it to occupy his mind, but it does keep his hands busy, making it easier to concentrate.

No response from Jii. What's taking him so long?

Kaito will have to add a heat emergency kit to future heist plans. He has his disguise covers (gels, patches, etc) from a/b/o to scent-receptive to scentless, depending on what he needs, but they aren't estrus grade. An easy mistake to rectify, but one he wishes right now he’d never made.

He can't figure out why he's so early. His heats come every six months like clockwork and have since puberty. Two months is an enormous aberration. Something’s wrong.

But he’ll have more time to think on it once he figures out how to leave the hotel. It can’t be as impossible as he’s making it.

“Think,” he mutters. He has to escape without anyone the wiser, or anyone discovering his identity. Which normally, okay, fine. But Hakuba knows his natural scent, and while usually a thin gel is enough, estrus intensifies everything to the point where backtracking through the hotel is dangerous.  Kuroba Kaito was never here. He can’t be, not with Hakuba’s sense of smell, able to pick up trace scents for a week or so afterwards.

They call Hakuba the Bloodhound, half-compliment but pejorative in the way that all references to their shared canine ancestors are. Still, he tracks better than most trained police officers and is more tenacious than a dog with a bone. Probably not politic to make that comparison either, but at this point Kaito doesn't care.

Kudō doesn't have the same nose, nor the knowledge of Kaito's natural scent, but he is smarter, and it's just his luck that both detectives had been present.

Kudō is also dangerous in a different way.

Enemies. Rivals. Sometimes allies for a mutual objective, always for Kudō's benefit, never Kaito's, and always with the thrill of flight, after.

Not that he doesn't enjoy the challenge, that's half the fun.

Narrow escapes, the way Kudō pushes Kaito to be better, more adaptable...

That certain twist of his lip when he smiles.

Uh oh. Kaito is slicking up, strengthening his natural scent, even through his trousers. He should be thinking of anything but that. All he’s doing is making his situation worse.

The doorknob rattles, but Kaito's distracted, increasing the difficulty of the card manipulation, trying to fight down the surge of desire before he compromises himself; by the time he realizes someone's coming through, it's too late to do anything more than grab his cape and crawl under the table as the door opens.

Footsteps. Men's black dress loafers.

No discernable natural scent, and the faint touch of cologne.

So it must be Kudō. Who has scent covers almost as sophisticated as Kaito's, and definitely the kind unable to be purchased.

Kudō, who'd lived a double life as that little detective, who’d also worn a synthetic false scent, so Kaito has never known what he is. Kudō, who scent-masks even now.

The feet walk towards the ventilation, and Kaito lets out a mental curse. He’s not thinking clearly. Kudō must have followed his scent through the air circulation! Then they're turning to the conference table, moving closer, and Kaito prepares his sleep gas.

They pause before he gets in range. “I know you're there,” he says.

Kaito feels sweat bead down his nose as a small flicker of warmth pools in his stomach at his voice. Uh oh. He clenches his fists in the fabric above his knees, riding the new wave of tingling arousal, trying his best to ignore it, but it's like hiding behind a tree to escape an tsunami. Just from his voice.

Kudō peers under the table far enough away the gas won't work and Kaito knows he's been made, so he does what he can and scoots back towards the window. He shifts to his feet. He can open it and glide away—

But his hands, normally dextrous, fumble with the latch as as Kudō comes closer. That smell from earlier. It's him. He smells like expensive cologne and the spice of sex, and it covers Kaito's own like a caress, faint but unmistakably alpha.

Well, that answers that question.

Kaito _wants._ Now more than ever. But no, not with him. Too risky. He breathes in slow, trying to regain control, but he can taste him on his tongue.

He’s so fucked. Well, not really, but he wants to be.

“Don’t,” _come closer,_ he says instead, never letting his eyes leave Kudō's.

Kaito just wants to bend him over the table and fuck him. Using his own slick as lubricant, biting into his throat as he begs for it, having him helpless underneath him. Another surge of lust hits him.

Kudō’s just staring at him, mouth parted slightly. Then he blinks and says, “I covered your trail since I owe you for last time. But this is a one time deal, and it's dependent on you returning the necklace.”

But riding him sounds just as good. Hell, Kudō holding him down, teeth at his throat, pounding into him until he is used and raw sounds absolutely fucking amazing. He imagines Kudō wrapping the necklace around his wrists, kissing him as light refracts on the ruby and colors his skin passion red. “Why?” Kaito rasps as another wave tears through him at the thought. He's soaked, now. Kudō's nostrils flare. “It'd be easy to turn me in right now.”

“Not like this,” Kudō says, swallowing. Kaito wants to nip the line of his throat, cover it with dark bruises. “When I catch you I want it to be fair and square.”

“I'm not going to thank you.”

“I don't expect you to. But a heist during your heat?” he says, stepping forward, movements agitated. “What in the world were you thinking? Did you want to get caught?” Kudō asks, taking a step even closer.

Kaito tenses, but doesn't run. He should have by now.

He smells so good.

“I wasn't supposed to be—” Kaito falls to his knees as another wave hits him.

“You're on suppressants,” Kudō accuses, kneeling at his side, lifting his hand to either tear off his monocle and hat or check his temperature. Kaito flinches away and Kudō’s hand drops before it makes it to his forehead. “How long? How much are you off schedule?”

“That’s none of your business,” Kaito says.  He’s not on suppressants. They’re murder on hormone regulation. The risks far outweigh the benefits.

“Idiot. You're going into heat fever,” Kudō says. “You know that can kill?” His hand drops to the small of Kaito's back, and though he doesn't touch him, Kaito can feel the heat of his hand.

He suppresses a shiver. It's all he can do not to press into it.

“I'm not!” Kaito says. “They're strong for me.”

“Which means you usually push it like this, I bet.” He leans in closer so that his scent is almost overpowering, bleeding through his scent-blocker. Kaito wants to taste it from the source. He licks his lips.

Kudō moves in even closer, smelling him just under his ear at the curve of his throat, almost touching his skin. It would be so easy to press against him, to give in to what his body is telling him and spend his heat here.

“I don't need your help,” Kaito says, pushing him away. Even that touch is almost too much. His heats are always intense. Kudō knows nothing. “And I don't need your lecture.”

“The task force trackers will pick up on your scent if I leave you now,” Kudō says, voice thick. “They'd be here already if it weren't for me.”

“What do you want, a prize?” Kaito says, pushing himself off the ground, standing up and getting away so he can think more clearly.

But he can't.

Kudō's scent is filling the room, now, making it hard to think. Not only that, but his musk is much stronger and Kaito can’t help but let his eyes flicker down to the visible bulge in Kudō’s trousers.

Kudō grabs his arm in his distraction, startling him past his control.

Something deep and primal inside surges at his touch and Kaito _growls,_ rumbling deep in his chest, slamming Kudō against the wall, gripping his wrists so tightly they might bruise.

Kudō falls down, breaking Kaito’s grip with his body weight, kicks out in a low sweep and trips him, then straddles him and pins him down. He's rock hard.

They struggle for a moment and Kaito flips him, rocking against him as Kudō lets out a cry, holding his wrists above his head with one hand while the other puts pressure on his throat, sharp nails positioned right at his carotid arteries. Kaito doesn’t realize he’s leaned down and moved his hand until his nose is already pressed against Kudō's throat, scenting him.

Kudō tries to buck him off, but all that does is make them brush together again, causing them both to cry out, and Kaito sucks a hard kiss on his throat, letting Kudō's spice spill over his tongue. The struggle causes Kudō’s scent to spike. Kudō likes it rough. Makes Kaito wonder what else he’s been hiding.

But Kudō isn't done, and he bucks again and lifts a powerful leg, hooking it around Kaito and twisting and forcing him down so that Kaito is again under him, hands on his wrists above his head in a mirror move of Kaito’s.

They're both hard and panting, and Kudō rubs his cheek against Kaito’s, covering his scent. He trails his hands everywhere, lingering on his scent glands as he rubs his own scent into Kaito’s. “We can't do this here,” he says against his skin.

Kaito's honestly past the point of caring. He rolls up into Kudō's weight, causing them to brush together again.

Kudō gasps, mouths his jaw, and leans down for a kiss, tongue swiping against his bottom lip. Kaito opens his mouth, lets their tongues twine together. The kiss is filthy, wet, sloppy in the best kind of way.

He slips one hand out of Kudō's hold and goes to his tie, loosening it and unbuttoning his shirt from the collar down one by one as they continue kissing.

Kudō breaks the kiss.

“We can't—” he says, breathless as Kaito runs his hand down his chest to the band of his trousers, lingering on the line of his stomach.

“Can't we?” Kaito asks, breathing his air, continuing to rock against him, but there's too much fabric between them for it to do much.

Kudō unbuttons himself, pulls his cock out of his pants, and it's perfect. Beading with precome, Kudō's scent overpowering. Kaito's thighs are wet with slick, his trousers damp, his body _wants._

But he lifts Kaito’s shirt, and starts thrusting against Kaito’s bare stomach until he’s leaking a little more precome.

He swipes his palm across himself and touches Kaito’s cheeks, throat, wrists, covering him with his heavy musk mixed with come. Their scents are intermingled to the point where they're almost indistinguishable, which is what he thinks Kudō was going for, scent-marking him like they're mates. A single entity.

It's above and beyond a favor for a favor. It’s downright _aiding and abetting._

Kudō just claimed him. Kaito just let him.

 _Fuck_.

It only makes him want him more.

“That’ll do until we get you to a rut room,” Kudō says. “Are you able to disguise like this?”

Kaito pulls away with the last of his restraint. Kudō has his real scent now, so the monocle and wide brim really aren't going to do much anymore. Kaito's sorely tempted just to take it off, but the small part of rational thought still left grabs his hoodie and his sweats, pulling them over his suit. He removes his hat and monocle and puts the hood up.

It still smells like the disguise he'd used to infiltrate, and for a moment, Kaito's lost in a sea of disconnect with only Kudō’s smell to ground him. Then he’s slammed face first against the wall, Kudō pushing his legs apart and rubbing his cock against his ass and between his thighs to cover up the smell of his arousal. He struggles, but that only makes Kudō's thrusting more intense. (Which is kind of the point; Kaito's not getting enough friction, and he wants _more_ )

 _Mine,_ his scent says. _All mine._

Kaito only lets him because he knows what he's doing. It's probably the best method of escape without detection if he can trust him. Though it's considered very rude to be so free with one’s musk in public areas, mated pairs are given a lot more leeway when it comes to public scent displays, especially if it's new, because instincts are so strong. It's not unusual for new mates to be constantly covered in each other’s scent, and the fact Kaito's own smell was completely masked would be attributed to an enthusiastic partner.

Kudō pulls away, tucking himself back into his underwear and zipping himself back up. “Come on,” he says, panting. “We don't have much time.”

His hand wraps around Kaito's waist possessively, and they leave the conference room, Kudō's scent drowning everything out.

Kaito later has no recollection of making it to the front desk, high on the scent surrounding him, only the receptionist's quiet little ‘oh’ at their appearance bringing him back to himself, his head tucked against Kudō's shoulder to hide his face.

“Rut room. Now,” Kudō demands, almost a growl. His shirt is still unbuttoned, his tie loose, his hair wild, and his musk chokes everything else out.

She looks unnerved, but she bolsters herself and speaks, exuding her own alpha scent in challenge. “Sir, we've received multiple complaints about your alpha posturing. This is a family hotel.”

“I know,” Kudō says. He doesn’t apologize. “The confusion earlier pushed my mate into unscheduled heat, drove them into hiding, and I panicked when I couldn't find them. Rut room. Please.”

Kaito wrinkles his nose at the implication, but it's the truth. Vaguely.

Her expression turns from challenge to understanding, and her eyes flicker to Kaito, curious. “Sir, they're fully booked.”

“They're going into heat fever and I'm not sure how much longer we can wait. Please. It's an emergency.”

He slides over a black credit card, and the woman changes entirely as she reads the name. “K-kudō-san! I didn't know it was you!”

She's peering at Kaito now, and he shrinks back and hides behind Kudō's shoulder, like the helpless mate he's pretending to be, ever the consummate actor, holding onto his sleeve like a waif.

“We'll take any scent-dampened room, a broom closet, anything,” Kudō says.

“The honeymoon penthouse suite is free,” she says. “I can give you a discount for the trouble.”

“It doesn't matter what it is, we’ll take it anyway,” Kudō says.

And that’s how they end up in the romantic suite, with its heart-shaped bed, its massive shower, and a jetted tub big enough for two.

Once they get in there, Kudō releases Kaito and pushes him away like the touch scalds him, collapses into the chair by the window with a sigh, holding his head in his hands and taking a deep breath. He spends a few moments collecting himself. “I’m leaving once I shower. You can stay here as long as you need to.” A deep rattling breath. “Just, necklace, please,” he says, head down, holding out his hand.

Leaving? Oh no, no, no. Not with Kaito slick and _aching_. “You're assuming I actually agreed to give you the necklace, Meitantei,” Kaito says. “I never did.”

Kudō's head jerks up, his lips parted. “But—” his eyes flicker as he runs through the memories, then his expression hardens as he realizes Kaito's right.

“You took that on yourself,” Kaito says with a smirk, hood shadowing his eyes. “How unlike you to miss that. You're usually so thorough.”

“Give it back, Kid,” Kudō says, voice low. Threatening. It sends heat racing down Kaito's spine.

“Hmm…” Kaito says, tapping his chin. “No. I don't think so.” He walks closer to Kudō and the large penthouse windows, holding the large ruby up to the crescent moon. It doesn't glow. “But,” he says, drawing out the word, sing-song, “I can be persuaded to let it go. For a price.”

“I don't want any part of your games, Kid,” Kudō says.

Kaito taps his lips. “But you were so willing to be a part of them earlier,” he says, eyes wide in mock innocence.

“What do you want?” Kudō asks. It sounds pained.

“You aren't just going to scent-mark me and leave me all alone, are you?” Kaito says, pushing Kudō back in the chair, leaning over his lap with a knee between his thighs and pulling out the necklace, wrapping the diamond chain around his fingers. Kudō's hands settle around his hips, his grip tight but shaking.

The large ruby is teardrop shaped, and he traces the cool stone across Kudō's lips as Kudō closes his eyes, to his cheeks, down the side of his throat before hooking the clasp around his neck. It looks stunning on him in the moonlight. “A poor, lost, helpless little omega like me?” he says as he nuzzles his cheek against his throat, covering him with his own scent.

“There's nothing lost or helpless about you,” Kudō says, voice rough, and Kaito laughs against his throat before tasting him again, swirling his tongue over the scent gland, and rocking back as another wave crashes through him. “ _Ah!”_ Kudō rocks against his thigh.

“Deal?” Kaito asks, panting.

“Scenting me defeats the purpose of me getting you a room,” Kudō says, breathless as well. “I can't walk out of here with you all over me.”

“So what? You’re going to shower anyway, right?” Kaito says, lifting his palm and nuzzling at his wrist. “Wash me all away?” He licks it, wetting it thoroughly, moving up to his palm and tracing the outlines of his bones with his tongue, slathering him in mouth-scent. “Put your scent blockers back on and go back to being a respectable detective as soon as you walk out of this room?” He rubs his thigh against him.

Kudō _whimpers._

He does the same to his other wrist, letting his tongue linger. He tastes so good. “When you and I both know exactly the kind of consorting you've done with filthy,” _lick_ “dirty,” _lick_ “criminals.” _Lick._

He looks up. Kudō's watching him avidly, eyes blown, body hot and trembling underneath him, barely holding on to the last of his control. “You're in heat, you're showing signs of fever, you don't know what you're saying—”

Kaito laughs, backing off, leaning farther down and pressing his face against the outline of Kudō's cock, inhaling deeply as Kudō shifts, stills, makes an aborted motion for Kaito's head. He _wants._ “Oh Meitantei, is that what you keep telling yourself?” He drags his hand over it, unbuttoning him, unzipping slowly. Kudō lets him. Kaito looks up at him through half-lidded eyes, though the hood still covers his head. “When have you ever known me not to be in control?”

Then Kaito stands, stepping towards the bed. “You have your necklace. Go.”

“Does that work with everyone else?” Kudō asks. He doesn't get up.

“What?” Kaito asks.

“Your lies. Look at you. Your face is flushed, you're still sweating, and you're shaking. I can smell you from here. You're barely holding it together, aren't you?”

“And what of yours?” Kaito lets his gaze linger over his body, especially where he is straining against his pants. “You want more than repaying a favor. A lot more. Rutting against me, covering me with your musk when just your scent would have done.” His eyes meet Kudō's in a challenge. “I know what I want. Do you?”

The fact that Kaito is standing above him is a false power play. Kaito only has the illusion of control. Neither one of them is in control here.

For the longest moment, Kudō doesn't say anything.

Then he surges forward and crushes his lips against Kaito's in a bruising kiss, caging his face in his hands.

That's more like it.

They fall to the bed, Kaito tearing off Kudō's suit coat and shirt, leaving him just in a tie. He rolls over on top of his detective, pinning him to the bed, slotting his knee in between his legs to Kudō's grunt and grinding down on his thigh. He's just about soaked through, now.

He tears off his hooded jacket, and the sight of his face unadorned makes Kudō pause. “Kid…?” he asks, stunned.

“You have my scent,” Kaito bites out in explanation, takes off his coat and cape, fumbles with his buttons of his shirt, and when that takes too long, he rips it apart, buttons flying everywhere. “No point.” He kicks off his sweats but he has his white trousers underneath and damn if it isn't too many clothes and he wants to be naked. The seam tears as he rips them off and it leaves his suit ruined but honestly at this point _he does not care._

Kudō writhes underneath him, trying to remove the rest of his own clothes. He takes off the tie, wriggles out of his trousers somehow but he's still wearing the ruby necklace and Kaito finds that incredibly, unbelievably hot.

He leans down and they meet in another bruising kiss.

Naked, Kaito's omega musk hangs heavy in the air, and there's nothing hiding the fact that he’s slick and waiting for Kudō.

But first, Kaito's above him, Kudō's pinned underneath him with that luscious cock weeping, and Kaito owes him for slamming him against a fucking wall. He fights, trying to flip Kaito, but Kaito is adamant and Kudō’s scent spikes as Kaito keeps him pinned down.

He likes it. So Kaito hadn’t misread earlier.

Kinky fuck.

Kaito reaches over, pulls out his thick lube from his discarded coat on the edge of the bed, and Kudō surges up, biting at his lower lip, invading his mouth with his hot tongue, touching him everywhere, fingers molten. Kaito fondles his balls, and Kudō's hands grasp at his shoulders. He runs his fingers down his crease and swirls his fingertip around the muscle before dipping his finger inside, massaging him and pressing just so.

Kudō gasps into his mouth and clenches around him, and then he relaxes and lets Kaito prep him.

Kudō reaches up to the right half of Kaito’s face, tracing the ridges around his eye, cupping his cheek.

Kaito adds a second finger and Kudō tucks his face against his shoulder, nuzzling into his neck, letting out something close to a purr. “Meitantei, what—”

“Shinichi,” Kudō mumbles against his throat. “Your fingers are up my ass; I think you can call me by my name.”

Fair point.

He presses up and Kudō—Shinichi—jerks against him. The nuzzling turns into the scrape of teeth and the swipe of tongue as Shinichi leaves his own marks against his throat, starting at the scent gland below his jaw.

Once he's lubed and ready, Kaito marks him methodically, the same way Kudō marked him, stroking his cock and dragging it over Shinichi's wrists, his throat, his face as Shinichi leans into it, moving down to mark his inner thighs, covering each and every scent gland until Shinichi smells completely of him.

 _Mine,_ his scent says. _All mine._

“Lewd,” Kaito says. He's covered in kiss marks and bites and come. “My Shinichi,” he says as he pushes in. Shinichi lets out a gasp as Kaito says his name. He's hot and tight, and Kaito rocks slowly at first, letting him get used to the feel of him. Then he parts his legs, lifting them for a better angle. “My debauched little alpha.”

“If it feels like this, I'd be happy to be your anything,” Shinichi says and twists his hips, impatient for Kaito to move, so Kaito does, rolling into him and making Shinichi cry out.

It feels nice, so Kaito does it again, chasing the sensation. It's not long before it starts building, and as the rush comes, his movements become more frantic, rougher, skin slapping against skin.

The sound drives him to thrust harder, and Ku—Shinichi arches and claws down Kaito's back as he pounds into him, biting into his shoulder to muffle his howl. Shinichi’s beginning to swell into a knot.

That sight sends Kaito over, bright sparks coursing their way through his body as he whites out, and he falls forward on top of Shinichi, panting hard.

He's coming, but he's nowhere close to sated, and he’s empty and _aching_ to be filled. Shinichi lets out a noise close to a whine as Kaito pulls out and falls to the side, rumbles something wordless against his chest, then falls back, stretching out.

Shinichi’s hand skitters down to his slit, slides a finger in easily he's so slick. Shinichi plays with him a moment. “I'm going to show you why you'll never need any alpha but me,” he says. Kaito just thinks of that burgeoning knot, thinks of how it would be inside him, and presses back against Shinichi's hand.

Shinichi flips him over, and Kaito shifts to his knees, upper half of his body still against the bed, spreading himself for him. “You really want this,” Kaito hears him say from behind him, surprised. Kaito wishes he could see his face.

“How'd you figure that one out?” Kaito asks, tone dripping with sarcasm even as Shinichi guides himself to him, prodding him with his tip.

“Kept staring at Hakuba. Wasn't sure,” he says.

‘What does Hakuba have to do with anything?’ Kaito wants to ask. “Are you always this talkative when topping?” Kaito says instead, because he doesn't want to talk about Hakuba during sex, then grunts as Shinichi thrusts into him, hard.

Shinichi cries out as Kaito's body tightens around him in response to the intrusion. Oh. Oh, that's nice. He's all the way in, barely fits but all the way in, body pressed up against Kaito where they meet, and it's so nice. “Only with you,” he says, and that has a load of implications Kaito doesn't want to think about.

“You kept watching him,” Shinichi continues, and _what._

“What?” Kaito repeats out loud as Shinichi pulls halfway out and then rocks back in, slamming into him as if to punctuate his words.

“You kept watching him instead of me,” Shinichi says, slamming into him again, driving him forward.

Yeah, only because Hakuba knows his scent and knows who Kuroba Kaito is when he's not wearing a mask. But his smell—”You bastard,” Kaito says in realization. Because that tantalizing smell, the one that made him hard, the one that surrounds him even now, was him. Is him. Thrust.

_Fuck._

“You territorial alpha bastard,” Kaito says, and he laughs. Thrust. “Your jealousy set me off.” Thrust. It was the first time they'd been at one of his heists together. Shinichi'd gone into rut thinking he was competing for Kaito’s attention against _Hakuba_ of all people, ugh. Thrust. As if there were any competition there.

“What?” Shinichi asks, pausing in his movements.

“Oh don't act like you don't know,” Kaito says, driving himself back onto Shinichi’s cock since he stopped moving, circling his hips to get the angle he needs. “Your stupid pheromones bleeding _ah-_ all over the place.”

Shinichi's hands tighten on his hips, threatening to bruise. “That’s supposed to only happen with life mates.”

“You’re the one who did it,” Kaito says, then it hits him. “You did that thinking I was an alpha, too,” he says, secretly pleased. It means he wasn't just fucking him because he was currently a willing omega, he wanted him no matter what.

“Shut up,” Shinichi says, rolling his hips again.

“Make me,” Kaito taunts. So Shinichi picks up the pace and pistons into him. He reaches around, starts stroking his cock as his breath catches, and Kaito's trapped between his hand and his cock as he continues to fuck him hard, and Kaito admits that's a way to shut him up pretty firmly.

Kaito rides the wave of pleasure as Shinichi rocks into him, getting close again but never quite falling over the edge. But he feels something, next time Shinichi thrusts; it's a little tighter, there's a little less give as he slides all the way into him.

He's still pumping him, and Kaito’s close. Very close.

When he rocks into him again, Kaito feels him twitch, and he nearly takes Kaito with him as he pulls back out. The next thrust inside him is tight, and that and Shinichi's constant, relentless hand sends Kaito over the edge.

He cries out, tightens in reflex, and Shinichi growls again, swells inside him as he follows Kaito over. It's fucking amazing, Kaito's beyond full, and he can feel him filling him even more, can feel each little twitch of his cock as he pumps him full of come.

Shinichi tries to pull out, but jerks Kaito back with him. “Oh,” he breathes.

“Someone got a little too excited,” Kaito laughs breathlessly, wrung out.

“Perfect,” Shinichi groans. Kaito agrees. Perfect knot, tying them together. _Fuck._ Kaito pants as he feels him twitch again, feels more hot come surge inside of him.

Shinichi pulses inside him again, and lets out a soft noise, falling over on Kaito’s back, keeps coming in small spurts as he tweaks Kaito's nipple, noses into his neck. He rubs Kaito's stomach, the low span between his hips, strokes it while kissing his hair and cheek and neck.

Shinichi's cock twitches again, and it's too much. Kaito's dripping, come covering his thighs.

Shinichi rubs his hands over him, dipping into his come, reaches around, massaging him low on his stomach, splaying his hand across it.

It's possessive.

It's hot.

They maneuver themselves so they're face to face, and Shinichi lays him back against the bed, easing the stiffness in Kaito's spine. They have to move as one, and it hurts when Shinichi pulls too far, but it’s a much better position to be stuck for a time, for both of them.

Shinichi kisses him, soft and languid and perfect. Shinichi's still releasing into him, little by little, and he puts his weight on Kaito, warm and heavy, still wearing the priceless ruby necklace, and traps him in an embrace. Kaito inhales deeply, their scents intermingling in the air setting his blood on fire again.

He pauses as Kaito pokes insistently against his stomach, and he lifts himself a bit. Shinichi's hand trails down to where they're joined and puts his hand on Kaito's stiff cock.

“Hard again already?” Shinichi asks. “You must really like me filling you up,” he says, satisfied. Smug bastard.

“Shut up,” Kaito says.

“Make m— _umph_ ,” Shinichi says as Kaito kisses into his open mouth, sliding inside his mouth and stroking his tongue with his own, running it over the ridges on the roof of his mouth. Kaito has absolutely no problem with shutting him up, thanks.

Their kissing remains relaxed and slow as Shinichi still intermittently releases inside him, Shinichi stroking him almost lazily, thumbing his cockhead.

Kaito breaks the kiss to breathe, and Shinichi says, so quietly he can barely hear it, “I drove you into heat,” he says, tone full of wonder.

Kaito tenses, but before he can think too hard on what that tone means, Shinichi strokes faster, and Kaito falls back against the sheets, head back, baring his throat to him almost on instinct as he rocks into his touch as much as he can, locked together like this. Shinichi leans over him, puts his teeth to his throat, bites down just enough to sting as he strokes him to completion, Kaito arching into his touch as he comes again, viscous white covering his stomach and chest.

Shinichi dips his finger into it, traces around his nipple, first the left, and then the right, then follows the path him made with his tongue as Kaito attempts to regulate his breathing, also licking up any errant drops that made it this far up.

The pulses come farther apart the longer they're tied together, but Shinichi still hasn’t softened completely yet, not enough to pull out, and so they lay there, Shinichi nuzzling him, kissing him, licking him, both of them something close to sated, (but not quite; the sharp burning, the _want_ is still there, deep inside Kaito, and as Shinichi softens, he starts to ache again).

The ruby necklace with its thousands of little diamonds surrounding the main stone is covered in come. It's going to have to be scrubbed of DNA before it’s returned, Kaito thinks idly, but he can’t help but be addicted to the sight of him wearing it.

With one more shuddering pulse, Shinichi’s finally soft enough to pull out, and he does with a sick pop, more come leaking out as he does, falling to the bed beside him, wrapping his arms around him and pressing his face against the scent glands in his neck.

Kaito’s never gone through heat with a partner before, and he’s unsure what to do now. A shower, certainly, and then a change of sheets kept for just such a purpose.

Is he going to stay for the three or more days it’s going to take to get through this? Because Kaito’s never had the edge taken off so quickly.

And the fact that Shinichi’s territorial scent display with Hakuba had triggered him, the fact that his body had shown that it approved...sure, they’d worked for a mutual goal a time or two. But this…

Like a hall of mirrors. Everything is on its head.

Kaito doesn't mind, so long as he doesn’t turn him in. And he hasn’t so far, even when he could have. He definitely could have by now, but instead they're here. Together in bed, Shinichi wearing the product of his heist like a badge of honor, covered in his scent and in his come and willing—no, eager—to be topped by an omega.

Not that he doesn’t give as good as he gets mind. Kaito shifts in remembrance.

A ringtone not his own makes Shinichi let out a low, irritated growl and scramble for his discarded clothes. “I’ve got to get back to the Task Force. They're looking for me.”

A spark of alarm spikes in Kaito. “Oh?” he asks, keeping his voice even. It would be the perfect time to leave, for all he knows his face and scent.

“I’ll be back,” Shinichi says, giving him a long, lingering kiss.

“I’ll be here,” Kaito says against the corner of his mouth. “Shower first?” he reminds him.

“R-right,” Shinichi says, pulling away. “I won't be long.”

“Don't be,” Kaito says, licking his lips.

Shinichi turns and takes a few steps towards the ensuite, Kaito watching that glorious ass.

Then he looks down at Shinichi's unlocked phone, laying innocently on the bed. The message he’d sent to Jii is just under the one from Nakamori.

He'd sent it to the wrong number.

Kaito calls out to him, “Want to save water?”

Shinichi grins. “That sounds like an excellent idea.”


	2. in pain or ecstasy

**Summary for the Chapter:**

> Shinichi’s sure he’s in over his head.

**Notes for the Chapter:**

> Heads up for updated tags. I also went ahead and added the "mpreg" and "lactation kink" tags though they show up next chapter. Fyi.
> 
> This fic will have at least one more chapter, maybe more depending.
> 
> warnings this chapter for more possessiveness, minor one-sided hakukai, and less minor one-sided hakushin
> 
> Alpha, Beta, Omega with the capital letters refer to social roles within any given social circle.

Shinichi unclasps the priceless ruby necklace, setting it gently on the table next to the bed, and heads into the ensuite.

The honeymoon suite has a luxury shower with several heads and so many options it takes even Shinichi a second to figure it out.

But he does and steps into the running shower, standing so the water pours over him, hoping to clear his head. He should be leaving already, but Kid is right. He’ll at least need to clean his smell off him.

But Shinichi doesn't want to.

He doesn't want to leave, either.

Every time he takes a step, a delightful lingering ache makes itself known. A certain delicious pleasure exists in that sharp jolt up his spine.

Even through the water, he can still smell Kid’s rich natural scent lingering on his skin; something deep inside him, something primal and instinctual curls in satisfaction at their intermingled musk. That will fade the longer he spends underneath the water, and he scowls at the thought.

Shinichi misses his heady alpha scent, seeing as it's what drew him in the first place, but the ease in which Kid changes and discards even something that is supposed to be immutable like scents—his omega scent is something precious, something he was never meant to know, and that makes it all the sweeter.

The shower door is frameless, the size of the tiled area preventing the glass from steaming up, the door into the other room open, so Shinichi can see Kid bent over, pawing through his abandoned clothes, palming something.

Shinichi licks his lips. His naked body, slender. Broad shoulders. Muscles, toned and lean in the way of a dancer or gymnast. Hips flared slightly wider in the way of omega men. All usually hidden under an exquisitely tailored suit.

An impression of Shinichi's teeth linger on Kid's neck. Signs of their lovemaking color his body. Deep red scratches on his back. Bite marks on his shoulder. Bruises on his hips.

Shinichi wants him, so much so he's stirring again from the sight alone. He has to fight the urge not to step out, grab his arms as he's bent over and take him all over again.

Kid grabs his phone and types up another message. Then he glances back at Shinichi, infuriating grin on his face, before turning to a drawer and pulling out a tube and several bottles. Then several sex toys. He unboxes one and makes a lewd gesture with it.

He knows.

Of course he does.

But it doesn't stop Shinichi from wanting.

It's not like Shinichi is unfamiliar with omegas, or even omegas in estrus. Hattori’s one, and Shinichi has been around him during his heat more than once. His instincts always expressed themselves in patrols around Hattori’s location and hovering around, much to Hattori's annoyance. Hattori, for his own part, seemed barely affected even without suppressants, working between his flare ups.

He’d actually been closer to rut as Conan watching people fumble around Ran. Which had been something, since he was supposed to be too young to be influenced by his secondary nature. It was a good thing bratty kids could get away with a lot. Ran could take care of herself, but as her Beta Shinichi still felt the need to do something about it.

Maybe it's Shinichi's preference for alphas. Maybe it’s because Hattori is his friend, a known element. Pack.

Not like Kid.

Kid, who he’d thought was an alpha.

Kid, who'd manipulated his scent and fooled everyone, his true nature covered with the most sophisticated and complex synthetic scent Shinichi has ever encountered. It smelled so real he'd had no doubt. Not even Haibara’s were that good, which is why he’d continued using Agasa's scentless ones.

Kid steps into the shower, bringing several bottles with him and placing them in the backsplash niche. He turns on the head above the tiled seat spanning the width of the shower, but he doesn’t stand under the water at first. The shower head he's using is detachable, and Kid holds it above his head, letting it massage him as he tilts it back.

It has the effect of baring his throat in a seductive display of submission. That, coupled with his smell, is almost more than Shinichi can stand. He turns away from him, breathing hard. The water scarcely dampens his smell.

Kaitō Kid had seemed different this heist. More scattered. Less focused on Shinichi, treating him as the lesser threat. More focused on Hakuba. That had made Shinichi angry for reasons he couldn't justify or explain at the time.

The reason had only hit him once Kid had called him out on it.

Rut, the territorial displays of aggression and scent marking did happen with alphas—and betas and omegas too, whatever people liked to say—but humans, as beings of higher reason, were expected to hold to a higher standard of behavior than their animal counterparts and control themselves. Most did. Instinct was no excuse. The only time it was close to acceptable was when a mate was in heat.

Thus, the fact Shinichi had let himself get so worked up was embarrassing. It was more than presumptuous, practically claiming him as his mate even before he had. But it wasn’t fair. Kid heists were _his_. Kid was his rival to face off against. What interest did Hakuba have in him? What right did he have to be there and chase after him? And for Kid to acknowledge Hakuba over him?

It _burned_.

And it didn’t matter Kid could be anyone, that his face he usually wore could just as well be a mask, that his primary nature could be male or female. It didn’t matter that Shinichi only knew he was an alpha and nothing else.

Shinichi had wanted to show him he was the only one worth looking at. He'd worked himself into a frenzy, forgetting to change the scent mask he'd gotten into the habit of wearing as Conan in his anger.

Maybe he wouldn’t have changed it even had he remembered.

When he'd smelled Kid's scent intermixed with an unfamiliar omega’s, it had been more than he could bear. It shouldn't have felt like a betrayal. Even Hakuba would have been better than some random nobody.

Discovering the omega scent had been _him_...it set something deep inside Shinichi ablaze, something that's still burning and threatening to leave Shinichi ash.

Once he'd found out, he couldn't let him get discovered, not like that. Even if Shinichi hadn't owed him a favor, no one deserved that. He hadn't had any other motive, not at first. Regardless of the way his body acted, he was better than that.

But Kid pushed, as he always did, and Shinichi couldn't help but rise to meet his challenge.

Shinichi turns back to watch Kid lather a cloth with scentless soap, rubbing his chest until his nipples pebble. They're pinked from the hot water, and Shinichi wants to bite, to suckle, to turn them red. He runs the cloth slowly down his stomach to stroke himself, and Shinichi is fighting to keep his distance from him at the erotic act. The act is glacial in its motion, and the cloth lingers, like he’s luxuriating in his own touch.

A delicious satisfaction lies in Kid being affected so greatly by Shinichi's scent, enough to have driven him into early heat. He'd affected Kid as much as Kid had affected him.

Yes, he'd claimed Kid so he could help him escape against his better judgement, but Kid had _claimed him back._ And that changed everything.

Shinichi is Kid's choice, and that makes Shinichi's primal instincts sing.

He's powerless to resist. Shinichi takes a couple of steps forward, presses Kid against the tile and kisses him. The hot water falls on his shoulders and back, pressure hard and water almost sharp. It's almost too hot to stand, pounding on his skin.

Shinichi grabs the soapy cloth from him and rubs it in soft circles over his chest, moving up to his shoulders, across his back.

One kiss turns to two, to three, to more as Shinichi cleans him. Kid pulls away for a moment, biting his lip, then grabs another cloth, wetting it and soaping it, and then gently rubs Shinichi where he’d scented him, wiping his own scent away.

It feels a little like ritual. It feels a little like heartbreak.

Something in his scent must give him away, because Kid's expression changes, and he nuzzles his throat, their soapy wet chests sliding together. His erect nipples brush against Shinichi, leaving tingles where they touch him, and he can feel him hard against his hip.

“I'm just going to have to wash again,” Shinichi points out.

“...So?” Kid says. He pulls Shinichi to him and starts purring, a low rumble deep in his chest as he wraps his arms around him, washing his back. This close, Kid’s scent surrounds him again, and something in Shinichi settles. “Need you,” Kid says, reaching for one of the bottles he brought with him. “It's already been too long.”

It's lube.

Kid pulls away, turns, rests his forehead against the wall, arm above his head. He adjusts the showerhead so that water runs down his back.

Shinichi's mouth goes dry. He takes a moment to watch him rinse, and to admire. Soap lather sluices off his body, down his back, past his hips.

Shinichi lets it all rinse away before he grabs a cloth and touches the small of his back. Shinichi strokes him, runs the cloth over the round of his ass and down between, over his rim, to the sex just behind his testicles, running the cloth over them before dragging it back up.

Kid makes a soft noise, adjusting his hands on the wall for support, pressing into his touch. So, so, eager.

Shinichi grabs the lube and spreads it over himself, knowing exactly what Kid wants. He spreads Kid's thighs with his knee, fingering his sex with more lube to make sure he’ll stay slick, then lines himself up, gripping his hip with one hand, and thrusts into him, splitting Kid like he was made for it.

Kid lets out a happy sigh, presses back against Shinichi as he sinks further inside him. “Mmmmm,” he says. “ _Shinichi_.”

The intimate use of his name sets a fire low in his body and Shinichi chases it, rocking into him deep, their bodies pressed together, sheathed to the hilt.

Shinichi thrusts into him, and it feels amazing. He does it again, and again, Kid hot and willing...

But something's missing. It's not enough.

“Let me see you,” Shinichi says, caressing his back. He expects Kid to refuse, or tense up, but he pulls out, and Kid turns for him, lifts a leg and wraps it around Shinichi's hip as Shinichi braces him with his arms.

He’s beautiful. Shinichi never expected to see his face without the shadow of a brim. Shinichi cups his jaw, staring into blue eyes. He's not quite sure of the emotion he sees there but it makes it hard to breathe.

“My good looks leave you speechless?” He ruins it by opening his mouth, his grip firm sliding Shinichi inside him.

“That’s assuming you have any,” Shinichi says, thrusting into him as deep as he can in this position.

“Such a rude mouth,” Kid wraps both his arms around his neck, kissing him and swallowing his protest as Shinichi moves to support him more fully. Kid works his hips and the angle is rough and not enough but there's something satisfying about being able to kiss him and thrust into him at the same time, about Kid's cock wet and slippery working against Shinichi's stomach. He backs him against the tile for support and lifts him fully.

All illusion of washing is gone. Shinichi's grip is tight on Kid's wet thighs as they cage his hips, Kid jerking his hips for a deeper and deeper angle, wrapping his legs around his body as Shinichi moves his arms to support him better, to line them up for more than shallow thrusts.

It's still not enough, so Kid wraps his legs tighter around Shinichi, driving himself onto Shinichi's cock in short uneven thrusts.

He pauses for a moment, leans over and kisses him again before continuing to move. He bites Shinichi's lip, maps his mouth, tastes him sweetly, and so Shinichi backs up, almost slipping even on the rough mat, and sits down on the wide ledge, out of the water. He can control the angle better, slides in him just right; Kid clenches around him and grabs hold of him tighter, thighs tightening around him.

“ _Shinichi_ ,” Kid moans his name against his neck.

His name a prayer on his lips. Shinichi starts to swell again as Kid drives himself down on him, again and again, fucking himself hard on him, so warm, so hot, so perfect. Then Shinichi is coming again, locking them together. Knotting twice in under an hour; Shinichi can hardly believe it. Kid’s body is only so accommodating, and he grips him tight around his knot, causing Shinichi to mumble curses against his skin.

Shinichi can't help but continue to rhythmically roll his hips, trapped in his heat. Though they're locked, he doesn't pull enough to hurt; each little thrust makes Kid quiver around him, and he hopes it is as good for Kid as it is for him.

The water dulls Kid's scent, but it's still heady. His cock is tight between their stomachs, Shinichi's buried deep as possible inside him.

Kid clings to him tightly, still rocking his hips in tight little circles, desperate for enough friction to get off.

Shinichi fills him, clings just as tightly back, completely undone. He buries his nose in his neck, in his scent, nuzzling him with his cheek before scraping his teeth against his throat as Kid tilts head back, following it with a hot tongue.

 _His._ Acknowledgment of his submission, and a promise. His to care for. His to provide for. His to protect. Mostly symbolic these days but no less poignant.

Shinichi kisses him again. His hand moves to the span of his hips, and Shinichi parts their bodies just enough to grab hold of him and start stroking, and Kid gasps into his mouth. Shinichi thumbs his head, pulling gently in a slow rhythm.

Shinichi's release is muted, less; he'd spent himself out earlier with his eagerness. Alphas didn't need to knot to come, and they didn't knot every time they coupled; the purpose was to ensure procreation, but conditions weren't always ideal. When an alpha did knot, it took some time to produce more come, given how much was spent.

Shinichi, comfortable enough to knot. Kaitō Kid, heat triggered and accelerated by Shinichi's own pheromones. Shinichi's still hesitant, but his body is saying forever. He's almost inclined to listen to it. Forming a new pack together, Kid, heavy and whelped—

Kid lets out a needy little noise, spills into his hand. Shinichi puts his hand into the water, letting it rinse away as Kid pants hot against his shoulder, breath mixing with the steam.

“Meitantei—” Kid says against his skin when his breaths have slowed.

“Shinichi,” Shinichi interrupts him.

“Shinichi,” Kid repeats. He has a note in his voice Shinichi would call vulnerable—if it were anyone else.

“Yeah?” Shinichi says. They're still locked together, Shinichi riding the low waves of his release. Kid's warm around him, his body firm and solid in his lap.

“...Thank you,” he says.

“Thought you said you weren't going to thank me?” Shinichi says, and ducks to tease his nipple with his tongue.

It takes away enough of Kid’s wit all he can say is, “Shut up.”

Shinichi says against his skin, “And here I thought you'd say something about finding other ways to keep my rude mouth occupied.” But he obliges, if only to flick his nipple with the sharp edge of his tongue before worrying it with his teeth.

“Just you wait until I have you at my mercy again, I'm going to make you _scream_ ,” he pants, curling his fingers in Shinichi's hair.

Shinichi lifts his head, meets his gaze with a challenge, “Big words. Care to put your money where your mouth is?” He's looking forward to it. The exquisite way Kid pinned him down before; he wants to feel that again. “Or are you all talk?”

“You wish.” Kid pushes his head back down, rough. The way his fingers dig into his hair sends tingles through his scalp.

Shinichi latches on, scraping his nipple with his teeth, sucking, nursing at it until it is that beautiful shade of red.

He moves up, nipping at his collarbone, licking the curve of his neck before finding the mating bite and biting again, just enough to hurt.

Shinichi can't stop the happy rumble in his chest. _Mate._ “Kid,” he says aloud against Kid's neck, sated.

“Aren't you pleased with yourself,” Kid grumbles, but he says it fondly. His fingers dance up Shinichi's arm, across Shinichi's shoulder, up to his neck, then he leans over and bites him, sharp teeth sinking into his neck. A sweet pain that sends a jolt of pleasure deep inside Shinichi. He thrusts up into him as Kid clenches around him. “ _Shinichi_ ,” Kid says, satisfied, then licks the bite.

“Very pleased,” Shinichi says. “You all right?” he says, hand falling to massage his thigh, the other rubbing against Kid's lower back. It's a bit of a cramped position.

“I’m flexible,” Kid says. Yeah, is he _ever_. “You feel so good,” he says, nuzzling Shinichi's bite, scenting it.

“Ye _ah,_ I could say the same,” Shinichi groans as Kid finds a sensitive spot under his jaw, biting it softly before nuzzling against him, chest rumbling happily.

The water falls behind them like rain as they sit, tied together in the most intimate of ways, Kid rocking together with him in the most shallow of thrusts.

“Kid?”

“Mmm?” he mumbles. It sounds almost sleepy though he’s wide awake.

“...You're welcome.”

Kid tightens his arms around his neck, face pressed against the curve.

“And can I tell you something else?” Shinichi says.

“Of course,” he says.

“I don’t want to leave.”

“Meitantei, are you saying…you’re attached?”

“No!”

“You are! I knew it!” he crows, nuzzling against him again, squeezing him tight.

“Currently. Physically,” Shinichi tries to backtrack, but it’s already too late. He can feel him smiling against his skin. It's...not so bad, he guesses.

“Sure,” Kid says, clear he doesn't believe him.

They sit there together for a while longer until Shinichi twitches one last time, and then he's spent. But it's comfortable like this. He doesn't want to leave. His alpha instincts are strong, and that's half the problem. The other half is just how lovely he is.

Perfection right in his lap. _Mate,_ Shinichi's instincts say. With some reluctance, Kid rises from Shinichi's lap now that Shinichi's knot is almost gone, using Shinichi’s shoulders to balance himself.

He stands, then Shinichi feels heat rising to his face as come dribbles down his thighs. Kid seems shameless as he stretches, steps into the water again.

Shinichi follows, staying close, and Kid rolls his eyes, but lets him. Less distracted with his heat sated for the moment, Kid cleans him quickly but thoroughly with the scentless soap, but doesn't bother doing himself as well, which mollifies Shinichi somewhat. His scent is dampened but not gone, and he'll mark him again once he returns.

Leaving him alone in the room is one of the hardest things Shinichi has ever had to do, and he regrets it almost immediately, turning back in the hall and staring at the door with longing.

Needs must, but.

When Shinichi steps into the exhibition room, he finds the task force gone and the room cleared.

A shadow moves in the half-dark room, far from any of the displays. “You're late. Everyone has already left.”

As if he couldn't tell that himself. “It couldn't be helped,” Shinichi says to Hakuba. Hakuba's solitary presence is certainly convenient, and it wouldn't be too terribly hard to send a falsified mail. The other detective shoots him a considering look, watching him with a cool, steady gaze. Shinichi shifts.

Hakuba steps in front of him at an awkward angle, forcing him to turn. His suit is still neatly pressed, but his trench coat is rumpled. He fusses with his clothing, head down. “Yes. I'd gathered. Despite the conflict of interest, indubitably.”  

Shinichi tenses for moment, then relaxes as he scans the room and finds the reason for his behavior.  “And what is that supposed to mean?”

“I'm neither senseless nor stupid,” he says, “And you two are hardly subtle.”

“What are you talking about? ” Shinichi says.

It’s a poor deflection. The dry look Hakuba shoots him would tell him, if he didn't already know. “You absolutely reek of semen,” Hakuba says irritably. Shinichi sniffs discreetly, but he doesn't smell anything. He was _sure_ they'd cleaned well enough. “I can't even imagine how that happened, nor do I want to, but I dare say it explains your unprofessional behavior this evening.”

“Unprofessional? Excuse me?” Yes, he had been in rut at the heist itself, but he'd thought he'd hidden his ire towards Hakuba.

“I was told you were the great detective of the East. Then again, that information did come from Hattori-kun.”

Shinichi rumbles deep in his chest in a low, rattling growl at the insult to Hattori.

“Quite,” Hakuba says, instead of rising to the challenge. “Walk with me.”

Shinichi doesn't want to, because it's a command; who does he think he is—

“Please,” Hakuba adds in a gentler tone, and with a brief look at the cameras Hakuba maneuvered them to avoid, Shinichi nods.

They step outside and out of the range of the hotel's surveillance, and Hakuba's shoulders fall and he relaxes.

“I transferred here because a great thief that had never been caught became active again.”

Shinichi stays silent; Hakuba continues. “I wanted to prove myself, and how better to do it than with a thief that had never been caught? My father was willing to indulge me. I had his resources, and my grandfather's lab, and I managed to narrow the search down to a particular district of Tokyo. From there, it was simply a matter of cross referencing his physical characteristics and his suspected age.”

“And?” Shinichi says.

“Your hostility is amusing but not necessary,” Hakuba says. ”I enrolled at a particular institution on the strength of my conclusions. Imagine my surprise when I came face to face with my new classmate and he smelled nothing like he should.”

“What's your point?” Shinichi asks.

“I’m sure you know. It's unusual for someone with that level of infiltration expertise to be as careless as he was tonight.”

“So you're telling me you're classmates with who you suspect to be,” Shinichi says, trailing off, though they probably have already reached the tail end of plausible deniability.

“Exactly. As a matter of fact, he’s my Alpha twice over,” Hakuba says. “In both educational and private circles.”  He leans back against the side of the building. “It’s cute he thought he could hide from my nose.” He taps the side of it.

Shinichi carefully doesn’t react. Legal Alpha...that's something. School packs are one thing, and it says a lot of about Kid’s personality that he managed to keep hold of his class pack with the constant jockeying, but the fact he's Alpha of his private pack? _Hakuba's_ personal pack? That's just as good as acknowledging they're close friends.

Ran's his Alpha, and she had easily absorbed Hattori and Kazuha-chan into their pack. Granted, packs didn't always necessarily reflect close friendships, his thorny interactions with Sonoko—who was more Ran's friend—proved that, but he'd still put her needs above non-pack, and not just in deference to Ran.

Is that what this is? A _Vetting?_

Hakuba watches him, but when Shinichi remains silent, he continues. “What makes it even more unusual is he has consistently fooled my nose in the past.”

Shinichi has had enough. “Why are you telling me this?”

“He isn't fond of me,” Hakuba says.

“He wouldn't take his eyes off you,” Shinichi snaps out immediately, following it with a growl.

Hakuba's nose twitches. “You're jealous,” he says with some surprise. “I had not thought you compromised to this extent.”

Shinichi keeps silent, furious at himself.

“It isn't often an alpha ruts over another alpha’s scent,” Hakuba muses.

“You have a problem with that?” Shinichi asks. Alphas are very much his preference. He'd been gone for them since he first met Ran and not much has changed since then.

“Not at all. Just thinking out loud.” Hakuba shifts closer, circling Shinichi. Shinichi tenses at his prowling, but doesn't do anything in response. Not for a Vetting. “That must have come as some surprise, but you went through with it anyway.”

Shinichi grits his teeth at the reminder Hakuba also knows Kid's omega scent.

Hakuba pauses, leans in. Waits for his permission, and when Shinichi doesn't move, he cradles Shinichi's neck, thumbs the concealer over the scent gland where Kid had sucked that first hard kiss, inhales deeply. “You're keeping your scent uncovered now,” he says before pulling away. “It’s nice. You should keep it free.”

“Insulting Hattori, this conversation...what is it you want?” Shinichi says. He's uncomfortable with him so close, but at the same time, an unfamiliar alpha so close to his neck—he can't help his body's reaction to the threat of danger.

“You haven't figured it out already?” He’s so close Shinichi can’t help but be a little aroused at the threat. Judging by Hakuba's smirk, he knows, and it is intentional.

A finger down the curve of his neck, sharp claw at his throat. “Some, yes. A particular motive, no. The alleged perp, as close as you claim to be...I would have already acquired enough evidence for a warrant,” Shinichi says.

“Yes,” Hakuba says. “Circumstantial, but you know as well as I do the doors that can open.”

“Then why?”

“As I said, he isn't fond of me, and perhaps for good reason. But who he is, what he does...you see past it, just like I do. Else you wouldn't have put yourself in this position.”

“There are worse things,” Shinichi says.

“Exactly. What I found, and what I thought I'd find were two very different things, but by the time I figured that out, it was too late,” Hakuba says. He voice is wistful, filled with regrets.

Shinichi lets out a wry little laugh. That would definitely go straight to Kid's head. He'd had it wrong. Kid wasn't gone for Hakuba, Hakuba was gone for Kid.

“You make him careless, Kudō-kun,” Hakuba says. “Be sure you're prepared for that responsibility.”

Definitely a Vetting.

“And who are you to him that you’re Vetting me?” Shinichi asks.

“Someone that doesn’t want him to get hurt.”

Avoiding the question. “You want him,” Shinichi says. “You _like_ him.”

“Don’t tell him. You’ll ruin our little game,” Hakuba says in the space between them. Then he slots their lips together, running his tongue over his lower lip.

Shinichi melts for a second as the smell of alpha surrounds him, relaxes him, parting his mouth and returning the kiss, letting him in. Then he comes to his senses, growls, and pushes him off, slamming his back against the wall and grabbing his throat.

“What in the hell was that for?” Shinichi asks, snarling.

“Pass that on for me, would you?” he says, completely unconcerned. In fact, judging from the feel of his pulse under Shinichi's hand and the half-lidded eyes, he likes it a little too much.

Well. No small wonder they'd both ended up pursuing the same perfect omega. For a brief moment, Shinichi wonders if Kid would like—then he dismisses the thought. “He chose me,” Shinichi says instead.

“So he did. Welcome to the pack, Kudō,” Hakuba says, dropping the honorific.

Shinichi drops his hand, and Hakuba straightens up, then adjusts his clothes.

“And for the record, you did a good job of covering your scents. From anyone else,” Hakuba says. “But I suppose hiding yours for so long has left you out of practice in regulating them. You'll need to fix those tells for his sake.”

“You're the one that really called me down,” Shinichi says, voicing his suspicions.

“Yes. A very inconvenient time, I am well aware, but as I only knew you through hearsay, I needed to acquaint myself further with you as soon as possible.”

So many things Shinichi had assumed to be true aren't. “You're his Beta,” Shinichi says.

Hakuba nods. “I'd like to think so.”

“Isn't that a conflict of interest?”

“Isn't it?” Hakuba laughs. “I believe we both are aware now where the other stands. Oh, and you're welcome, by the way. For the Joining gift.”

“What?” Shinichi asks, confused. “What gift?”

Hakuba just smirks, and then turns and walks away, leaving Shinichi scowling after him.

He's still a little bewildered by it as he saunters back to their shared room, and though he doesn't like to admit it even to himself, he's a little worried about Kid leaving. He's not the type to let himself be restricted by his heat. Only his scent gave him away towards the end, and even then barely.

As he enters, he finds Kid waiting by the door.

“You smell like Hakuba,” Kid says, narrowing his eyes.

How hadn't he seen they knew each other before? “He kissed me,” Shinichi says, still confused and irritated and not thinking about the consequences of his words until Kid presses him against the door, devouring him.

Shinichi sags as his legs give out in the surge of arousal, lets Kid and the wall support most of his weight as they kiss hard, bruising. Shinichi's clothes are gone almost before he thinks about trying to get them off, and the next thing he knows he's being carried like a bride and thrown on the bed hard enough to bounce.

 _"_ **Mine** ,” Kid growls deep enough to reverberate, practically feral, before pouncing on top of him, straddling him, pinning his wrists to the bed.

Oh, Shinichi thinks in a daze. That's what Hakuba had meant by gift. He'd correctly deduced Shinichi's concerns and manipulated Kid into going into full rut. But he'd called their coupling a Joining. More serious than mating, not quite a marriage, but…

Kid just needed a partner to ease his heat.

Right?

Shinichi tilts his head back in submission, baring his throat as they slot together. Kid ruts against him furiously. “Mine,” he repeats more softly as he presses his nose to his skin, nuzzles his scent everywhere Hakuba touched, making sure his own scent covers his _overpowering_ and Shinichi is lost in his everywhere touch as he runs his hands over his body, slides against him, kisses him and touches him and tastes him and feels him. _Mate_ , Shinichi agrees. _Mine._

Kid bites the mating mark, rocks against him again and again, and Shinichi goes limp as heat spreads through him, flooding his entire body like a wildfire. “Yours,” he says, he begs desperately. “Yours _please._ ”

And then Kid shifts, sitting upright, and suddenly Shinichi feels wet heat and jerks as Kid starts rocking against Shinichi’s cock, his thighs dripping with heat slick, making the slide sweet, omega musk thick and intoxicating and wonderful, and Shinichi's so close to filling him but after rocking once more, Kid climbs off Shinichi's thighs, parts them.

Shinichi bites his lip in anticipation; the temperature shift makes him shiver, left bereft of the beautiful cradle of his thighs.

“He did it just to rile you up, you know,” Shinichi says, hand falling to the top of his thigh to cover Kid's hand.

“I know. Bastard,” Kid says, giving Shinichi's hand a quick squeeze, “I don't know who he thinks he is,” he says, reaching down, coating his fingers in his own slick before using those same fingers to prod at Shinichi's rim.

“I've half a wonder if he didn't do the same to me,” Shinichi murmurs as Kid kisses the crest of his hip, the swell of his cock, because really, now that he thinks about it, some of his actions at the heist didn't make sense unless one took it in mind that he really was part of Kid's personal pack and looking out for him.

Damn, how much of a farce were those heists?

But then the thoughts are out of his mind because Kid is fingering him with two wet fingers, just twice to check his resistance before he's thrusting into him with a groan.

“Kid!” Shinichi cries out, not expecting the thickness of it, the immediacy, but Kid is impatient, caught in the throes of heat, lifting his hips and jerking him close even as Shinichi tightens his legs around him.

“Kid!” Shinichi calls out again as Kid nails him again and again with unerring precision, not letting up even as Shinichi turns into a shaking, sobbing mess.

When Shinichi comes, it's painful; too much, too soon, his body tenses and tries to release, but there's nothing left. Not after knotting twice in such quick succession. Kid doesn't stop, though, still thrusting deep into him, and Shinichi can't speak from the assault on his senses as it rocks through him, can't do anything but clutch at the sheets weakly, keep his head back as he tries to ride it out, oversensitive and overwhelmed as his release trickles out, pathetic, near dry.

And still Kid doesn't stop, even as Shinichi almost blacks out from the assault on his senses. Everything is too much, _too real,_ and Shinichi can't do anything but lie back and feel. The world narrows to electricity dancing through him, Kid, driving into him, the potent smell of omega in heat, the soft scratch of the sheets as he writhes, all mixed up in a confusing sensory mess.

And then he's rocking into him one more time, leaning over him, kissing him, holding him tightly like he's never going to be able to let him go.

Shinichi's so in over his head, isn't he? Because he doesn't want to lose this, the way his scent surrounds him, the heat of his touch, the way he breaks him and pieces him back together one kiss at a time.

He never thought it would be like this.

Kid collapses over him, his body sweaty and warm, his breathing still harsh. He nuzzles into his neck. “Shinichi,” he mumbles happily. And that's a little unfair because Shinichi doesn't know his name. He lets his legs fall as Kid cuddles against him. Kid the thief. Infuriating, but at the same time, Shinichi's match.

Pack, his instincts say, and Shinichi can't help but agree. Was he lying to himself earlier? Shinichi looks away, arms coming up to cradle his…boyfriend?

The ruby necklace sits on the table next to the bed like the red badge of all his sins.

No, Shinichi decides, he's leaning too strongly on his instincts. Even if Kid had waited for Shinichi to come back, hadn’t left when he could have, that doesn't mean anything. Even if Kid had gone into rut because he was jealous of the “attentions” Hakuba had given him. Kid was an omega in heat, Shinichi was the interchangeable alpha helping him out, favour for a favour. That was it.

But would it be so bad to be pack? Then to want their little fledgling pack to grow?

Omegas that didn't want children usually took shots or pills during proestrus, but considering human nature, and given how highly fertile omegas were during estrus, all rut rooms came equipped with complimentary emergency contraceptives upon request, just in case. Surprise heats weren't unusual, if not very common, due to the havoc suppressants and the like played on omega biology. So Kid would take them and it would be like nothing ever happened.

But just for a moment Shinichi lets himself imagine it. Kid, happy and round and pleased to be whelped with Shinichi's pups, ready to co-parent the newest little members of their pack, then it fades away into the realities of their situation.

Detective and thief. Shinichi shouldn't even be here. The thought makes his heart clench. Once they left this room, things wouldn't change at all. And he would be left with just the thrill of facing him during heists. It would have to be enough.

“What are you thinking about, Shinichi?” Kid asks, hand caressing his face.

“Nothing important,” Shinichi says.

“Looked important,” Kid says.

Shinichi answers with a kiss instead. Might as well take advantage of it while it lasts.

“You’re avoiding the question,” Kid says against his lips.

“Not really. How can I focus on anything else when I have you in front of me?” Shinichi says.

Kid watches him for a long moment like he doesn't believe him, but smirks and says, “That's true. By the way, how soon can you go again?”

Shinichi lets out a loud groan, Kid laughs, and the moment is forgotten. But as he rolls over towards the table to grab a dildo to help Kid with his heat, his eyes linger on the ruby necklace.

But then he turns his attention back to Kid, determined to forget the true distance between them.

For a little while, at least.

**Notes for the Chapter:**

> Next up: Kaito makes a decision, there's a timeskip, and the Ekoda group worry over their resident magician.

**Author's Note:**

> This has an incredible amount of worldbuilding and backstory from my previous attempts to play in omega verse that never went anywhere. I don't really touch on it much, but this has a lot of that behind it. I've too many projects on my plate to continue it at the moment, but I might add on to it in the future if there's enough interest, and it would probably include mpreg.


End file.
